Idle/Power Problems? Troubleshoot Here

[rcannon]

Any trick to getting the front O2 sensor out? It is frozen solid. Does it come loose with an open end wrench if you pull very hard? I'm afraid of breaking the flexible exh bellows. I've put on liquid wrench a few times to no avail.

[echase76]

Lots of liquid wrench/PB blaster and the proper tool. Almost any autoparts store will loan you the proper socket set for O2 sensors. Lots of muscle and if it is really stuck I know people have used a torch to heat them up.

Maybe someone else will chime in on if hurting the flexible bellow is a concern.

[abscate]

Acetone and ATF (mixed 50-50 vol/vol) is regarded as the best penetrant.

Apply daily for three days while the car sits - time is your friend here. Put the car up on ramps so you can get leverage, and use the loaner tool so you can really torque those things.

[pistrix]

Hi everyone,

I have a strange (to me) idle problem that I believe is most probably caused by a vacuum leak: When the car is moving (faster than approximately 30kph) and when I depress the gas pedal, the rpms decrease well below 850rpms, the engine stumbles and then either stabilizes on 850rpms or die. When the car is stationary, there is no such problem at all - after depressing the gas pedal, the rpms drop to about 1000rpm and then to 850rpm without any dip below.

Is there any valve in the vacuum system of the car that opens when the car is moving? I suspect there should be such a valve and that I have a vacuum leak after that valve. Do I have a leak in EVAP system? I believe I once read somewhere that the carbon canister is vented only when the car is moving?!?

My car is 1995 850 n/a and I cleaned/replaced/checked all the things necessary: replaced O2 sensor, water coolant temperature sensor, distributor cap and rotor, ignition coil and wires, airbox thermostat; cleaned IAC, MAF and throttle body; checked PCV system. The only thing I didn't systematically check is the vacuum system...

Any help would be greatly appreciated.

Cheers,
Jan

[matthew1]

Unstickying this and tucking it inside Links to MAJOR forum topics - 850, S70, V70, C70 & V70-XC to keep the top of the topic list from growing too tall. That will remain at the top of the forum.

[Stressed out jack]

Hi so I'm new here to volvo, just bought this car and learning about it. Have been having issues with idle and over heating. Maybe I'm in the wrong place but ran the codes today am getting MAF and the heat sensor (sorry if I called it the wrong thing) anyway iv replaced the MAF and it help temporarily then sputtered out on died again. Unplugged it and plugged it back in and ran fine one the way home. Tested again and same codes. I'm worried there's some sort of other issue I'm not seeing. Also not related but figured I'd mention, just in case if it is related, I'm having issue with the interment panel odometer stops working from time to time and the tachometer doesn't count miles, also getting break light sensor when pushing on the breaks even though they are working.